'\" t
.\"     Title: zmq_ipc
.\"    Author: [see the "AUTHORS" section]
.\" Generator: DocBook XSL Stylesheets v1.76.1 <http://docbook.sf.net/>
.\"      Date: 03/10/2014
.\"    Manual: 0MQ Manual
.\"    Source: 0MQ 4.0.1
.\"  Language: English
.\"
.TH "ZMQ_IPC" "7" "03/10/2014" "0MQ 4\&.0\&.1" "0MQ Manual"
.\" -----------------------------------------------------------------
.\" * Define some portability stuff
.\" -----------------------------------------------------------------
.\" ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
.\" http://bugs.debian.org/507673
.\" http://lists.gnu.org/archive/html/groff/2009-02/msg00013.html
.\" ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
.ie \n(.g .ds Aq \(aq
.el       .ds Aq '
.\" -----------------------------------------------------------------
.\" * set default formatting
.\" -----------------------------------------------------------------
.\" disable hyphenation
.nh
.\" disable justification (adjust text to left margin only)
.ad l
.\" -----------------------------------------------------------------
.\" * MAIN CONTENT STARTS HERE *
.\" -----------------------------------------------------------------
.SH "NAME"
zmq_ipc \- 0MQ local inter\-process communication transport
.SH "SYNOPSIS"
.sp
The inter\-process transport passes messages between local processes using a system\-dependent IPC mechanism\&.
.if n \{\
.sp
.\}
.RS 4
.it 1 an-trap
.nr an-no-space-flag 1
.nr an-break-flag 1
.br
.ps +1
\fBNote\fR
.ps -1
.br
.sp
The inter\-process transport is currently only implemented on operating systems that provide UNIX domain sockets\&.
.sp .5v
.RE
.SH "ADDRESSING"
.sp
A 0MQ endpoint is a string consisting of a \fItransport\fR:// followed by an \fIaddress\fR\&. The \fItransport\fR specifies the underlying protocol to use\&. The \fIaddress\fR specifies the transport\-specific address to connect to\&.
.sp
For the inter\-process transport, the transport is ipc, and the meaning of the \fIaddress\fR part is defined below\&.
.SS "Binding a socket"
.sp
When binding a \fIsocket\fR to a local address using \fIzmq_bind()\fR with the \fIipc\fR transport, the \fIendpoint\fR shall be interpreted as an arbitrary string identifying the \fIpathname\fR to create\&. The \fIpathname\fR must be unique within the operating system namespace used by the \fIipc\fR implementation, and must fulfill any restrictions placed by the operating system on the format and length of a \fIpathname\fR\&.
.sp
When the address is *, \fIzmq_bind()\fR shall generate a unique temporary pathname\&. The caller should retrieve this pathname using the ZMQ_LAST_ENDPOINT socket option\&. See \fBzmq_getsockopt\fR(3) for details\&.
.if n \{\
.sp
.\}
.RS 4
.it 1 an-trap
.nr an-no-space-flag 1
.nr an-break-flag 1
.br
.ps +1
\fBNote\fR
.ps -1
.br
.sp
any existing binding to the same endpoint shall be overridden\&. That is, if a second process binds to an endpoint already bound by a process, this will succeed and the first process will lose its binding\&. In this behavior, the \fIipc\fR transport is not consistent with the \fItcp\fR or \fIinproc\fR transports\&.
.sp .5v
.RE
.if n \{\
.sp
.\}
.RS 4
.it 1 an-trap
.nr an-no-space-flag 1
.nr an-break-flag 1
.br
.ps +1
\fBNote\fR
.ps -1
.br
.sp
the endpoint pathname must be writable by the process\&. When the endpoint starts with \fI/\fR, e\&.g\&., ipc:///pathname, this will be an \fIabsolute\fR pathname\&. If the endpoint specifies a directory that does not exist, the bind shall fail\&.
.sp .5v
.RE
.if n \{\
.sp
.\}
.RS 4
.it 1 an-trap
.nr an-no-space-flag 1
.nr an-break-flag 1
.br
.ps +1
\fBNote\fR
.ps -1
.br
.sp
on Linux only, when the endpoint pathname starts with @, the abstract namespace shall be used\&. The abstract namespace is independent of the filesystem and if a process attempts to bind an endpoint already bound by a process, it will fail\&. See unix(7) for details\&.
.sp .5v
.RE
.SS "Connecting a socket"
.sp
When connecting a \fIsocket\fR to a peer address using \fIzmq_connect()\fR with the \fIipc\fR transport, the \fIendpoint\fR shall be interpreted as an arbitrary string identifying the \fIpathname\fR to connect to\&. The \fIpathname\fR must have been previously created within the operating system namespace by assigning it to a \fIsocket\fR with \fIzmq_bind()\fR\&.
.SH "EXAMPLES"
.PP
\fBAssigning a local address to a socket\fR. 
.sp
.if n \{\
.RS 4
.\}
.nf
//  Assign the pathname "/tmp/feeds/0"
rc = zmq_bind(socket, "ipc:///tmp/feeds/0");
assert (rc == 0);
.fi
.if n \{\
.RE
.\}
.PP
\fBConnecting a socket\fR. 
.sp
.if n \{\
.RS 4
.\}
.nf
//  Connect to the pathname "/tmp/feeds/0"
rc = zmq_connect(socket, "ipc:///tmp/feeds/0");
assert (rc == 0);
.fi
.if n \{\
.RE
.\}
.sp
.SH "SEE ALSO"
.sp
\fBzmq_bind\fR(3) \fBzmq_connect\fR(3) \fBzmq_inproc\fR(7) \fBzmq_tcp\fR(7) \fBzmq_pgm\fR(7) \fBzmq_getsockopt\fR(3) \fBzmq\fR(7)
.SH "AUTHORS"
.sp
This page was written by the 0MQ community\&. To make a change please read the 0MQ Contribution Policy at \m[blue]\fBhttp://www\&.zeromq\&.org/docs:contributing\fR\m[]\&.
